Method of molding plastic shoes



May 17, 19,49. J. J. BOOTH 2,470,089

v METHOD 0F MOLDING PLASTIC SHOES Filed sept. 2s, 1944' @u @l A v l r /ga? if Z/ A-1' a Z5 j] INVENToR,

Patented May 17, 1949 UNITED STATES ATENT OFFICE 3 Claims.

This invention relates to the shoemaking art vand has as its principalobject Ito provide a method of forming a shoe formed or molded of asuitable plastic material or materials in a single piece or unitarystructure, possessing desirable texture, plasticity, flexibility, colorand nish.

To attain these desirable characteristics in lsuch an article ofmanufacture the invention provides a method wherein a mold of suitable'design, permitting of the introduction thereinto at suitable places ofthe requisite quantities of materials, which will unite and bond into afinished, one piece shoe, as the molding and curing processes aredeveloped, the finished product to possess the desired characteristicsindicated.

Novelty is not claimed herein for the injection or other apparatus forloading or injecting the materials into the mold, since conventionalstructure may be employed, and such are shown in the accompanyingdrawings.

Steps in the process are pointed out in the following descriptiontogether with the accompanying drawings, in which:

Figure 1 is a, schematic, end view of a mold and .injection apparatus invertical section.

Figure 2 is a plan view, partly in section, taken on line 2-2 of Figure1.

Figure 3 is a side elevation of the inner mold form showing section ofshoe thereon, and

Figure 4 is a side elevation of the inner mold form per se.

In the several views, like references indicate similar elements, inwhich I0 is a conventional apparatus for injecting plastic material atdesired temperatures and suitable pressures through ports or nozzles I Iinto suitable receiving ports I2 of my mold I3, while I4 is a structurefor supporting mold I3 in such a manner that when the mold is broughtinto operating relation with the injection apparatus nozzles II will bebrought into sealed registry with receiving ports I2 of the mold. Anysuitable means, such as a hydraulic ram or pressure apparatus (notshown), may be used Ito bring and retain the mold and injectionapparatus into operative relation. One part of the outer mold I3 isrigidly attached to support I4 and the other part is guided intooperative position -by guide pins I5 received by openings I6 inrespective parts of the outermold I3. The outer mold I3 is provided witha cavity I'I in the form of the outer surface of the shoe to presentlybe molded and is adapted to receive the inner form I8 in the shape ofthe inner surface of the desired shoe to be formed. Inner form I8 isprovided with a ID the discharge shank I9 and an extension 2|] forretaining the respective mold parts in desired relation during necessarymanipulation, to facilitate which extension 2i) is provided with slottedopenings 2I for receiving studs 22 threadedly engaging support I4. Themold parts I3 are provided with guide and retaining pins I3a, to bereceived by suitable openings in the shank I9 of the inner form IB asthe assembled mold is brought into position. The space or cavity thussecured is the exact shape and form to provide the desired thickness ofthe iinished shoe in all its parts. To further facilitate manipulationof the parts, compression springs 23 are operatively positioned betweensupport I4 and extension 20 so as to be compressed, as parts of outermold I3 are brought together about the innermold I8 and operatively withthe injection apparatus and exert a pressure tending to eiiectseparation of the parts of mold I3, as the molding lcycle is completed.For maintaining desired working temperatures in the molds they are, ormay be provided, with openings 24 for suitable media to be circulated byconventional means, which media are employed at temperatures necessaryto effect proper temperature control in the molds.

The mold I8 may be provided with projections 25, which may be used asspacers for the mold parts, and to create desired artistic designs onthe nished shoe, as well as ventilation openings at 'desired positionsin the shoe structure.

Space at the juncture of the mold parts usually will be found adequatefor escape of entrapped air from the mold cavity. However auxiliaryopenings 2'6 are provided when desired to facilitate the flow ofmaterials being introduced into the mold.

While only two openings I2 are shown for receiving the material into themold, it is obvious that any number may be provided to eiect proper owof materials of desired or varied texture, plasticity, porosity, coloror the like to make a completed shoe having all desired characteristics.The operation of forming a shoe is readily performed by closing the moldand inducing the proper temperature by means of the circulating mediumand bringing the molds into position to receive the plastic materials ofthe desired consistency, color, etc. and of proper quantities, and atthe proper number and positions from the injection apparatus to form theshoe, and maintaining these materials in the mold for such period orcycle of time, and at temperatures and pressures required to secure thebonding and curing thereof into a shoe of one piece. It will be readilyunderstood by those skilled in the art that as materials vary incharacteristics or properties, adjustments and variations of the severaldetails of the apparatus may -be required to effect the desired results.These Variations may include temperatures, pressures, number andlocation of introduction points for the material as well as escape ventsfor air and overow of material and time cycle of operations.

While I have shown apparatus employing the injection method ofintroducing the plastic material into the mold cavity, I may load themold by hand, before bringing the parts together by suitable pressuremedia and then retain the closed -position for the required time cycle,pressure and temperatures required. Other factors are so similar tothose outlined as to require no further elaboration.

It will readily occur to those skilled in the art that reinforcings orinserts such as in the arch heel or toe, may be incorporated in the shoeby positioning these elements in the mold cavity so that the materialows about them in the manner desired and cures with such elements inplace.

Also the desired finish or design may be provided an any part of theshoe by the riish or design of the corresponding mold surface.

` `When the molding 'operation is completed the pressure is released onthe parts of the outer mold I3 and the compressed springsZS urge themold I8 and a part of the mold I3 away from the other? part of the moldI3, thus exposing a portion of the finished shoe. The'remaining portionof the mold I3 is then removed and the 1inished plastic shoesmanipulated 01T of its inner form I8 by hand oroth'er suitable means.

Most materials suitable for manufacture of plastic shoes will possesssuilcient elasticity to permit of ready removal from the mold i@ andprojections 25. Where other materials are used I may provide acollapsible. inner mold or provide for retractible projections 25 tofacilitate removal of the finished Yshoe from the mold.

Manifestly, the construction as shown and described is capable of somemodification and such modification as may be construed to fall within Yplastic material the scope and meaning of the appended claims is alsoconsidered to be within the spirit and intent of the invention.

What I claim is:

1. The Imethod of forming a shoe having a combined and integral sole,heel, and upper, which consists of introducing into a mold at separatepoints quantities of plastic materials possessing varyingcharacteristics but possessing the -common property of uniting togetherand vof molding the plastic into an unitary shoe structure includingsaid sole, heel and upper; and forming openings in said upper atpredetermined points during the forming operation.

2. In a method as setforth in claim 1, said mold having a greater Widthcavity throughout the sole forming portion, whereby the sole will bethicker than the upper, and will possess less flexibility.

3. In a method as set forth in claim 1, introducing into .the parts ofthe cav-ity 0f the mold of different colors, whereby parts of the shoewill have colors diierent from other parts.

JACK J. BOOTH.

pertenencias CITED The :following references file of this patent:

UNITED STATES, PATENTS are of record in the

